In a vehicle transmission system, an electronic communication wire transmits information collected by an input speed sensor to a computer controller. In a prior art transmission system, the electronic communication wire is routed through an internal area of the transmission case casting. The prior art internal area of casting is generally situated at the exterior of the transmission case opposite a piston pocket. The process of casting the area for internal electronic communication includes casting a large mass adjacent to the piston pocket. This mass increases the likelihood of porosity in the transmission case in the surrounding area. Manufacturing such an internal passage then requires angled machining to form the passage through the casting. Machining through a porous mass in the seal bore of the piston pocket could render the case unusable.
In one transmission system, the computer controller is situated adjacent to an area where sump oil is held. Sump oil may become aerated if allowed to communicate with rotating parts. Aerated sump oil may create foam and add accumulation to the transmission. Thus, it is important to restrict sump oil from the transmission's rotating parts.
FIG. 1 illustrates a prior transmission case 10′ design, which has been improved by the present invention. The prior transmission case 10′ includes an internal communication aperture 100 which provides a passage for electronic communication wires 102, 104 to connect an input speed sensor and a computer controller. The process of forming the internal communication aperture 100 requires angled machining through a casting behind the piston bore 106 of the transmission case 10′. The casting process is followed by angled machining, which could open potential porosity in the transmission case wall 108 at the piston bore 106.